Hi, I assume according to "Cocoa design patterns" book i'm reading that the retain function is implemented using something like this : - (int)retainCount // Returns the receiver's current reference count { int result = 1; // receiver not in table, its count is 1 void *tableValue = NSMapGet( [[self class] _myRefCountMapTable], self);...
Is there a Windows (or .NET) synchronization primitive that: can be shared across multiple processes on the same PC; represents a counter of how many threads are currently depending on a shared resource; is automatically decremented by the OS when a process abnormally terminates; and can be waited on by another process (and signaled wh...
I'm looking at the code for basic_string (that is bundled with g++ 4.2.1). The copy constructor makes use of a grab() function to "grab" a copy of a string (increment its reference-count): _CharT* _M_grab( const _Alloc& __alloc1, const _Alloc& __alloc2 ) { return (!_M_is_leaked() && __alloc1 == __alloc2) ? _M_refcopy() : _M_clone(__a...
I am currently in a situation like: struct A { shared_ptr< B > b; } struct B { shared_ptr< A > a; } shared_ptr< A > a(new A()); shared_ptr< B > b(new B(); a->b(b); b->a(a); I know this won't work, because the references would continue to point to each other. I've also been told that weak_ptr solves this issue. However, weak ptr has no...
What is the difference between Garbage Collection and Reference Counting in Mac OS X. Thanks and regards. Mahadevan S ...
I would like to implement a simple reference counting using smart pointers. The variable pointer represents pointer to stored object, reference_count represents total count of copies of the object. if we initialize an object using NULL: reference_count = -1 else reference_count = 1 copy ctor and operator = increment reference_count des...
Which type of the smart pointer (shared, scoped) would be for such a data structures the most suitable... Structure 1: //Class with cross-references to points p1, p2 class PointTopo { private: double x, y; PointTopo * p1; PointTopo * p2; public: PointTopo(double xx, double yy): x(xx), y(yy) {this-> p1 = NULL; this->p...
From what I've read about cpython it seems like it does reference counting + something extra to detect/free objects pointing to each other.(Correct me if I'm wrong). Could someone explain the something extra? Also does this guarantee* no cycle leaking? If not is there any research into an algorithm proven to add to reference counting to ...
I'm really confused. // initial class type TTestClass = class( TInterfacedObject) end; {...} // test procedure procedure testMF(); var c1, c2 : TTestClass; begin c1 := TTestClass.Create(); // create, addref c2 := c1; // addref c1 := nil; // refcount - 1 MessageBox( 0, pchar( inttostr( c2.refcount...
Hallo, I have some troubles understanding the python reference count. What I want to do is return a tuple from c++ to python using the ctypes module. C++: PyObject* foo(...) { ... return Py_BuildValue("(s, s)", value1, value2); } Python: pointer = c_foo(...) # c_foo loaded with ctypes obj = cast(pointer, py_object).value I'm...